Read Larry's post on the proofing of these bbls very carefully. He is absolutely spot on on this. I do not believe a single one of you can produce evidence that any flaw in a bbl, undetected by the proof house, has ever damaged a bbl. It is true that a few bbls which had passed proof have later failed. This is as true of steel bbls as damascus, incidently, possibly even more so. "Flaws" in a steel bbl are more apt to take the form of a seam, which may be undetectable from the surface, have just enough substance to stand proof & later through wear give way. A flaw in damascus is much more apt to be a localized area. I have fired a twist bbl with a known flaw (visable) going completely through the wall in the form of a crack approx ¼ long in a radial direction & about half that length in a longitudal direction with several 3 3/4de-1¼oz Rem Express factory loads with no further opening of this crack or any visable change to it's structure. When acquired, in the form of a parts gun, one side of this crack was dented in & the other raised in the form of a flap & you could look through it into the bore. An expanding dent plug was placed beneath it & the dent part raised & the flap hammered down til the crack was closed up & became barely visable. I don't recall the exact number at this point but several of these Express loads were fired from the "Firestone" via a long string. I did not really expect this bbl to "Explode" but did fully expect it to open back up with gas spewing from the aperture. This simply did not occur & was not even a trace of "Soot" on the bbls extremity.
I also read "DAMASCUS BARRELS- BEAUTIFUL BUT DEADLY" but do not recall any "Absolute Evidence" he gave to back up his opinion. It was based I believe in it's entirety on "Speculation" with the causes of the bursts he cited being un-determined. To me well over a century of Proof House experience carries much more weight.
PS; I do believe the "Flaw" in the above cited bbl was the result of being struck a blow on a sharp cornered object & then supsequently fired with the resulting "Obstruction" actually causing the crack to form. Never-the-less even with that much loss of integrity the surronding metal held up.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra